65 CHAPTER 4-6

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Figure 1. on a Fissidens . Photo by Janice Glime. – Mollusks Glistening trails of pearly mucous criss-cross mats and also seemed to be a preferred food. Perhaps we need to turfs of green, signalling the passing of snails and on searach at night when the snails and slugs are more active. the low-growing bryophytes (Figure 1). In California, the white desert snail Eremarionta immaculata is more common on lichens and mosses than on other plant detritus and rocks (Wiesenborn 2003). Wiesenborn suggested that the snails might find more food and moisture there. Are these mollusks simply travelling from one place to another across the moist moss surface, or do they have a more dastardly purpose for traversing these miniature forests? Quantitative information on snails and slugs among bryophytes is scarce, and often only mentions that bryophytes are abundant in the habitat (e.g. Nekola 2002), but we might be able to glean some information from a study by Grime and Blythe (1969). In collections totalling 82.4 g of moss, they examined snail populations in a 0.75 m2 plot each morning on 7, 8, 9, & 12 September 1966. The copse snail, Arianta arbustorum (Figure 2), numbered 0, 7, 2, and 6 on those days, respectively, with weights of Figure 2. The copse snail, Arianta arbustorum, in 0.0, 8.5, 2.4, & 7.3 per 100 g dry mass of moss. They were Stockholm, Sweden. Photo by Håkan Svensson through most abundant on the stinging nettle, Urtica dioica, which Wikimedia Commons. 66 Chapter 4-6: Invertebrates: Mollusks

In the Pacific Northwest, USA, unusual jumping slugs gastropods Punctum pygmaeum and Pumilla muscorum in the Hemphillia (Figure 3) prefer coarse woody among the terrestrial mosses Plagiobryum zieri, Hypnum debris or moss mats on decaying logs (Leonard & Ovaska cupressiforme (Figure 4), and Tortella tortuosa. From my 2003). Their ability to roll or flap violently may break their own observations, it appears that snails and slugs are surface tension, permitting them to move quickly, and common on moss clumps, but finding documentation on giving the appearance that they are jumping. Evidence also their use of moss evades even the aggressive Google suggests that they smear their slime trail, confusing search. potential predators. In Canada, some of these species seem Snails can sometimes occur in significant numbers in safe from extinction due to sufficient abundance, but others moss habitats. Their need for a moist environment (Pratt are endangered due to increasing patchiness of suitable 1935) would seemingly attract snails to the mosses as a habitats. The 1994 NW Forest Plan regulates ground moist substrate. Grime and Blythe (1969) found average disturbance activities on federal lands in northern morning populations of up to 8.5 Arianta arbustorum snails California to Washington, protecting "survey and manage" per 100 g dry weight of moss in early September at species, including several species of jumping slugs. Hence, Winnats Pass in Derbyshire, England. This was surpassed protection of these slugs can help in the protection of only by those on Urtica dioica (stinging nettle) reaching mosses in these areas. However, the Bush administration 14.4 and Mercurialis perennis (dogs mercury) reaching was not sympathetic to this protection and it could be lost 16.2. Nevertheless, it takes a lot of dry moss to make 100 at any time with a change in administrative philosophy. g. However, nighttime activity by many snails is likely to be greater, although little snails may actually seek refuge in mosses during the day. Furthermore, snails like Arianta arbustorum typically climb, often to a considerable height, to obtain food. Bryophytes just don't fit into this behavior pattern, so the behavior of Arianta arbustorum may not reflect that of the small snails.

Figure 4. Slug on Hypnum. Photo by Janice Glime.

Szlavecz (1986) determined that snail size plays an important role in their behavior. Although one might think that larger need to eat more, it seems that larger Monadenia hillebrandi mariposa (see Figure 5) instead spends more time crawling and less time feeding, Figure 3. Hemphillia glandulosa, the warty jumping slug, on permitting it to travel farther. Although it prefers leaf litter, moss. The two photos illustrate the variability in its coloration. Photos by Kristiina Ovaska. it consumes mosses as well (Figure 6). One would expect that size would also constrain movement among the bryophytes and restrict larger snails to the surface. Bryophytes as Home Because of their small movement space, bryophytes Wiesenborn (2003) observed snails in the Riverside can serve as safe sites for smaller snails. Birds can be Mountains of California and found that the active snails significant consumers of snails, particularly during preferred epiphytic mosses and lichens compared to plant migration (Shachak & Steinberger 1980), and bryophytes detritus and four sizes of rocks. They suggested that the can make the snails less conspicuous, if not hiding them epiphytes could provide these snails with food or moisture. completely. In terrestrial habitats, arachnids such as In the sub-Antarctic Marion Island, the slug Deroceros spiders and daddy-long-legs (Opiliones) are also predators caruanae lives in moist bryophyte communities as well as on snails (Nyffeler and Symondson 2001). While some on decaying bryophytes (Smith 1992). In boggy habitats, spiders can probably navigate the spaces within the moss gastropods have little choice but to travel across bryophytes mat, it seems unlikely that mature daddy-long-legs could (Stanisic 1996). In a study of bryophyte inhabitants in the manage without getting caught. In addition to the Bükk Mountains of Hungary, Varga (2008) found the arachnids, Carabid beetles prey on terrestrial gastropods Chapter 4-6: Invertebrates: Mollusks 67

(Symondson 2004). Some of these beetles use a pump In streams, it is likely that snails find mosses as a safe mechanism to extract the gastropod remains from its shell. site from the current. Habdija et al. (2004) rarely found any gastropods on bryophytes at velocities of greater than 70 cm s-1, whereas oligochaetes became more abundant at higher velocities. Flow rates are much slower within the moss mats, thus providing a haven for feeding where the current is unlikely to dislodge the snails and slugs. This also provides them protection from predators such as fish (mostly), ducks, shore birds, and amphibians (Pennak 1953).

Figure 5. Monadenia fidelis on mosses. Photo by Walter Siegmund through Wikipedia.

Figure 7. Prophysaon vanattae, the scarletback taildropper, can be found hiding under mosses. Photo by Kristiina Ovaska.

Figure 8. Prophysaon vanattae with eggs on a moss. Photo by Kristiina Ovaska.

Bryophytes as Food Snails and slugs have a rasping tongue that destroys the epidermis of tracheophytes (Grime & Blythe 1969), but what does it do to moss leaves only one cell thick? Apparently it makes them potential food (Szlavecz 1986), enabling these mollusks to consume even the tough capsule (Davidson & Longton 1987, Davidson et al. 1990). Nevertheless, the palatability index for bryophytes is low (Jennings & Barkham 1975). And snails and slugs seem to be less interested in grazing things with awns than those without. Robin Stevenson (pers. comm. January 2008; Figure 9) has seen Bryum argenteum that is completely Figure 6. Laboratory selection of foods by the snail grazed over, but never observed such grazing on an awned Monadenia hillebrandi mariposa. Upper: all data combined. Grimmia species. Could it just be that there is no nutrition Lower: juveniles vs adults. Redrawn from Szlavecz 1986. in an awn, or do they have trouble gliding across the furry tips of leaves? The slug Prophysaon vanattae (scarletback But awns may not deter all snails. Szlavecz (1986) taildropper; Figure 7) is one of those snails that seems to was able to identify the awned Grimmia trichophylla in the find a safe site under mosses on trees on Vancouver Island, feces of the California snail, Monadenia hillebrandi Canada (Kristiina Ovaska, pers. comm. 30 June 2009). But mariposa and also demonstrated that the spine tips of the it also hangs on epiphytic moss mats in the moist deciduous tracheophyte Selaginella hanseni did not deter feeding or forest there and may even lay eggs there (Figure 8). crawling. Michael Lüth has observed snails grazing on 68 Chapter 4-6: Invertebrates: Mollusks

Orthotrichum and Terry McIntosh has seen slugs grazing on other bryophytes, both indicating that the damage to the moss was similar to that shown in Figure 10 (Bryonet 12 January 2008). On the other hand, Frank Greven (Bryonet 13 January 2008) has seen this pattern as a result of grazing by isopods (wood lice). Robin Stevenson (pers. comm. 14 January 2008) agrees that isopods might be deterred by the awns, causing them to eat in such a pattern. But why would slugs or snails climb up the bridge coping to the moss for such a limited nutrient source?

Figure 11. Shell of aurora. Photo by David G. Robinson, USDA APHIS PPQ at Bugwood.org.

Algae growing on mosses, especially in the aquatic habitat, could be a prominent source of food. In the Negev Desert, adult desert snails (Sphincterochila zonata) fed exclusively on algae on the soil surface, creating an algal turnover of 142 kg hectare-1, despite being active for only 8-27 days in winter during the rainy period (Shachak & Steinberger 1980). Other Negev Desert snails feed on the mosses themselves. Trochoidea seetzeni feeds on shrubs there, but its feces indicate that it also feeds on the moss Desmatodon convolutus (Yom-Tov & Galun 1971).

Clearly for some slugs and snails there are bryophytes Figure 9. Bryum argenteum, a moss with no awns and a food that do indeed seem palatable. Ochi (1960) reported that source for snails and slugs. Photo by Michael Lüth. Conocephalum conicum (Figure 12) served as food for a slug. Merrifield (2000) found evidence of heavy grazing on epiphytic bryophytes, particularly Syntrichia laevipilus, of Oregon white oaks (Quercus garryana) in the Willamette Valley, Oregon, USA, and considered that either springtails or slugs were likely responsible. She considered that the abundance of gemmae may be a response to this grazing.

Figure 10. Grimmia pulvinata exhibiting grazing in a pattern typical of snail or slug grazing, but also known for isopods. Photo by Robin Stevenson.

That rasping tongue is not always enough to accomplish the task of obtaining nutrients from mosses. Oyesiku and Ogunkolade (2006) experimented with snails and the moss Hyophila crenulata. In their laboratory experiments, the snails (Limicolaria aurora; Figure 11) Figure 12. Conocephalum conicum, a liverwort that can gained the most weight when fed with H. crenulata paste. serve as slug food. Photo by Michael Lüth. The snails that had only unground moss actually lost weight. Those in the field experiment (restricted to H. Szlavecz (1986) compared feeding preferences in 31 crenulata) either lost weight or remained the same. Fecal individuals of the snail Monadenia hillebrandi mariposa. matter of the field snails had fragments of moss that had Collections of field feces indicated that they consumed lost the chlorophyll from their cells as well as that of Rhytidiadelphus sp. (Figure 13) and Grimmia trichophylla abundant algae and Cyanobacteria. The presence of these (Figure 14) in nature, among other things. In the lab, they snails on the moss was seasonal from April until October, preferred shrub and bay litter over mosses, but preferred when the moisture and lower temperature may have mosses and lichens over grasses and pine litter. Studies by provided a favorable habitat. This experiment suggests that Chatfield (1973), Williamson & Cameron (1976), and in this case the snail was unable to penetrate the cells of the Richter (1976) indicate that at least juvenile snails might do moss, making it an unlikely food source in nature. best on a mixed diet. Chapter 4-6: Invertebrates: Mollusks 69

Figure 13. Rhytidiadelphus squarrosus, a member of a genus that has been found in feces of the snail Monadenia hillebrandi mariposa. Photo by Michael Lüth.

Figure 14. Grimmia trichophylla showing awns. Photo by Figure 16. Capsules of Mnium hornum. Upper: Young, Michael Lüth. green capsules that are preferred by slugs. Photo by Michael Lüth. Lower: Mature capsules. Photo by Janice Glime. Davidson and Longton (1985, 1988; Davidson 1988, 1989) reported that several species of generalist slugs consumed bryophytes. Protonemata were readily consumed (Grime 1979). In Great Britain, capsules and protonemata of several mosses (Brachythecium rutabulum (Figure 15 ), Mnium hornum (Figure 16), and Funaria hygrometrica (Figure 17) were eaten preferentially to leafy gametophores by slugs (Arion spp.; Figure 19) (Davidson & Longton 1987, Davidson et al. 1990).

Figure 17. Capsules of Funaria hygrometrica. Photo by Michael Lüth.

Older capsules with spores were less preferred than the green ones (Figure 18; Davidson & Longton 1987; Davidson et al. 1990). Presence of moss cells of Brachythecium rutabulum and Mnium hornum in the feces of previously starved Arion suggest that the leafy mosses are not digested well (Davidson et al. 1990). Ferulic acid, Figure 15. Snail eating capsules of Brachythecium. Note the present in shoots but absent in young capsules of Mnium number of setae that are missing capsules. Photo by Janice hornum, is a phenolic compound that is only released after Glime. severe hydrolysis.

70 Chapter 4-6: Invertebrates: Mollusks

Figure 20. Arion subfuscus, a slug known to consume Mnium hornum. Photo by Gary Bernon, USDA APHIS at Bugwood.org.

Figure 18. Relative damage by slugs of sporophyte stages of two species of bryophytes. n=300-500 at day 0. LCI = late calyptra stage; EOI = early operculum intact; LOI = late operculum intact; OF = operculum fallen; EF = empty and fresh. Redrawn from Davidson et al. 1990.

Only trivial amounts of Brachythecium rutabulum shoots were consumed (Davidson 1989; Figure 15). Mnium hornum (Figure 21) was also ignored, but after 5-7 days of starvation Arion rufus (10-15cm long; Figure 19) and A. subfuscus (5-7 cm long; Figure 20) ate significant Figure 21. Mnium hornum shoots – a species that was quantities of shoots of this species. Arion hortensis still ignored in experiments until the slugs were starved. Photo by ignored the moss even after 7 days of starvation. On the Janice Glime. other hand, all three species of slugs readily consumed Funaria hygrometrica (0.4-6.5 mg wet weight per slug) in overnight feeding trials.

Figure 19. Arion rufus amid protonemata and liverworts. Photo by Alekas through Wikipedia. Figure 22. Young sporophytes of Funaria hygrometrica before spores form. Photo by Michael Lüth. Longton (pers. comm. 1996) has speculated that phenolic compounds that protect the leafy gametophytes Given the choice of capsules or vegetative material, deter herbivory, especially on perennials. This could both A. rufus and A. subfuscus preferred immature capsules account for greater herbivory on the Funaria hygrometrica of all three mosses (see Figure 23 ), with M. hornum being than on Brachythecium rutabulum or Mnium hornum. The top choice (Davidson 1989). Setae were generally phenolic compounds in the latter two species was released ignored, but A. subfuscus did occasionally eat M. hornum only after severe hydrolysis, leading Davidson et al. (1990) and B. rutabulum setae. All three slugs also ate to suspect that the phenolic acids might be tightly bound to protonemata in the laboratory, and for B. rutabulum and F. cellulose in the cell wall. The greater palatability of the F. hygrometrica the protonema was eaten just as much by A. hygrometrica (Figure 17, Figure 22) supports the general rufus and A. subfuscus as were immature capsules. In fact, theory that perennials invest more resources in defense dry weight consumption exceeded that of immature against herbivory than do annuals. capsules. Young shoots were also eaten, but less readily.

Chapter 4-6: Invertebrates: Mollusks 71

likely that hydroxycinnamic and phenolic acids in this species and in Brachythecium rutabulum provided this chemical protection against herbivory (Davidson et al. 1989). Stems of both species were apparently protected by ferulic and possibly m- and p-coumaric acid bound in the cell walls of the shoots (Davidson et al. 1989), explaining the preference of the slugs for capsules. On the other hand, when moss extracts were placed on communion wafers, the slugs ate them more readily, suggesting that chemistry alone was not the likely deterrent (Anonymous 1987; Davidson et al. 1990). Rather, some physical feature of the mosses, perhaps the cell wall, deterred these slugs. But what did the slugs derive from the consumed mosses? When they consume preferred foods such as lettuce leaf or carrot root, the resulting feces contain macerated, partially pigmented tissue (Davidson 1989). When they consumed bryophytes, on the other hand, large pieces of leaf, whole leaves, and even stem pieces remained. Most cells still contained green chloroplasts. Evidently the moss did little more than fill the gut. Even the preferred capsules were poorly digested, with capsule wall fragments, opercula, and peristome teeth remaining. Mature spores seemed unharmed, but immature spores seemed to have experienced some digestion, appearing broken, colorless, and shrivelled. Likewise, the protonema seemed to be digestible, resembling the lettuce and carrots in being macerated and colorless or brown.

Figure 23. Slug browsing on Leucolepis acanthoneuron. Photo from UBC website, with permission.

Figure 25. Slug on moss. Photo by Janice Glime.

This raises the question of whether slugs and snails actually eat bryophytes in the field, or is this a laboratory phenomenon where they have no other choice. For example, Jennings and Barkham (1975) found that bryophytes all gave low palatability scores when six species of slugs, including the three in the Davidson (1989) study, had a choice of foods. For whatever reason, it appears that at least some snails do eat bryophytes in Figure 24. Keeled slug, a common inhabitant of mosses in nature. Szlavecz (1986) found remnants of the mosses the Pacific Northwest, USA. Photo by Jeri Peck. Rhytidiadelphus sp. and Grimmia trichophylla in feces from snails (Monadenia hillebrandi mariposa) that had Davidson and Longton (1987) suggested that Arion been eating in the field. More green moss than brown hortensis was restricted by the physical structure of the occurred, whereas brown material was more common from capsule to consuming developing spores from broken consumed tracheophytes (Figure 26). Grime and Blythe capsules in P. commune; no spores were eaten from (1969) found bryophytes in the feces of four species of unbroken capsules. When approaching Mnium hornum, the snails out of the six examined from Winnats Pass, slugs would withdraw their tentacles, then retreat, Derbyshire, England, on 13 October. But then, suggesting some sort of chemical deterrent; they behaved tracheophyte foods are often less nutritious as the plants similarly in the presence of extracts from the capsule. It is prepare for winter.

72 Chapter 4-6: Invertebrates: Mollusks

habitat. But it is not necessarily all bad. Steinman (1994) opined that snail grazing could account for the apparent unresponsiveness of epiphytes following phosphorus enrichment in a woodland stream in Tennessee, USA, where bryophytes were prominent. And some bryophytes seem prepared to fight back. Ricciocarpos natans (Figure 28) exhibits molluscicidal properties that are active against the snail carrier of schistosomiasis (Wurzel et al. 1990).

Figure 27. Fissidens (Octodiceras) fontanus, a moss that seems to be vulnerable to snail grazing except it is protected by Fontinalis. Photo by Michael Lüth, modified by Janice Glime.

Figure 26. Comparison of green and brown portions of plant material eaten by the snail Monadenia hillebrandi mariposa. Modified from Szlavecz 1986.

Rosso and McCune (2003) found that mollusks on shrubs in the Pacific Northwest, USA, exhibited significant herbivore activity on the lichens. Bryophytes, on the other hand, had little change in cover between stems in exclusions and those available for herbivory. It appears that the mollusk herbivory on lichens may benefit the bryophytes by contributing to the successful competition of the bryophytes over the lichens in the understory of these forests. Indirect evidence suggests that slugs and snails graze capsules of Buxbaumia viridis (Gordon Rothero, Birds Figure 28. Ricciocarpos natans with holes where some feeding on moss capsules, Bryonet-l, 10 April 2003). Stark invertebrate has been nibbling. Photo by Janice Glime. (1860) relayed a story of the ill fate of Buxbaumia aphylla Slugs also eat hornworts (Figure 29). Bisang (1996) specimens on their journey from Scotland to England. A reported that they especially eat the green sporophytes. slug had inadvertently been included in the package and it managed to destroy the specimens. However, I have discovered that what appeared to me to be grazing on capsules of Buxbaumia aphylla is really only the splitting of the capsule top as it dries, and that this occurs on nearly every capsule. Grazing by slugs can be so severe as to define distribution of a species. Lohammar (1954) found that in northern Europe Fissidens fontanus (Figure 27) was absent in lakes where Fontinalis antipyretica was also absent. Others suggest that scarcity of Fissidens in some places is due to snail grazing (Gerson 1982). In the presence of Fontinalis, this smaller moss lives among the Fontinalis fronds where it is presumably protected from snail grazing by the inedible forest of Fontinalis surrounding it. It may be that in the aquatic habitat the snail effect on Figure 29. Phaeoceros carolinianus with mostly green some bryophytes is much greater than in the terrestrial sporophytes, a food source for slugs. Photo by Michael Lüth. Chapter 4-6: Invertebrates: Mollusks 73

Mussels secretion can be sticky. It is therefore no surprise that these animals have dispersal abilities. Some mollusks and other organisms can actually turn the relationship around and provide a home for the bryophytes. Yes, some of these animals actually have mosses growing on them. Neumann and Vidrine (1978) found Fissidens fontanus (Figure 27) and Amblystegium (Leptodictyum) riparium (Figure 30) growing on freshwater mussel shells.

Figure 32. Snails such as this one traversing epiphytic mosses in Japan may be effective dispersal agents. Photo by Janice Glime.

Slugs are able to disperse the brood branches of Figure 30. Amblystegium (Leptodictyum) riparium, a moss Orthodicranum flagellare (Kimmerer & Young 1995; known to grow on freshwater mussel shells. Photo by Michael Figure 34). These tiny branches become entrapped in the Lüth. secretions and are deposited in the ensuing slime trail. Kimmerer and Young found that these can be transported at Antifeedants least 23 cm from the colony, although the mean distance in their study was only 3.7 cm. Based on the fore-going discussion, it appears that at And it appears that the secretion increases the ability least some bryophytes are able to discourage browsing by of the propagule to adhere to its substrate without affecting slugs (Frahm & Kirchhoff 2002). Alcohol extracts of moss the germination rate. In fact, experiments by Davidson Neckera crispa (Figure 31) and liverwort Porella obtusata (1989) suggest that passage through the slug may enhance have antifeedant activity against Arion lusitanicus (Figure germination success. All plates containing mature spores 33). Extracts of 0.5% dry weight of the moss had low from slug (Arion spp.; Figure 33) fecal pellets produced activity, whereas those from the liverwort exhibited shoots, whereas only 80% of the plates with uneaten moderate activity at 0.05%. At 0.25% the antifeedant mature Mnium hornum spores and 70% of those with activity of Porella obtusata was complete. It is likely that uneaten Brachythecium rutabulum (Figure 35) spores this activity is not specific for slugs and may discourage produced shoots. insects, bacteria, and fungi as well.

Figure 33. Arion lusitanicus, a slug that traverses mosses, Figure 31. Neckera crispa, a moss that has antifeedant but finds Neckera crispa and Porella obtusata unpalatable. Photo activity against the slug Arion lusitanicus. Photo by Michael by Mogens Engelund, Wikipedia. Lüth. The ability of snails and slugs to glide across Dispersal Agents bryophytes and to climb setae to capsules suggests that It appears that slugs are not all bad in the bryophyte these animals may be important dispersal agents. Although world and may instead be a necessary vector for some some experiments exist on ability of spores to survive the propaguliferous taxa (Stolzenburg 1995). Slugs and snails mollusk gut, more experiments are needed. How (Figure 32) leave a trail of mucous as they go, and as you widespread are herbivory and dispersal among bryophytes well know if you have handled these mollusks, this that temporarily host these slow-moving animals? 74 Chapter 4-6: Invertebrates: Mollusks

Figure 34. Orthodicranum flagellare showing the tight Figure 35. Brachythecium rutabulum, for which the spores flagellate branches that can be dispersed by slugs. Photo by germinate better if they have passed through the gut of a slug Janice Glime. (Arion). Photo by Michael Lüth.

Summary Acknowledgments Snails and slugs have often been observed on Bryonetters have been wonderful in making their bryophytes. The white desert snail, Eremarionta photographs available to me and seeking photographs from immaculata, is common on bryophytes and seems to others. Robert Wallace helped me to understand the life prefer them as a habitat. The copse snail, Arianta cycle and structures of the rotifers. Paul Davison has been arbustorum is another known inhabitant. More helpful in providing suggestions and offering images. And quantitative studies have shown that some slugs and a long time ago Allen Neumann sent me a specimen of a snails prefer bryophytes. More active snails might be clam shell with Fissidens fontanus growing on it. Michael found at night, whereas tiny snails might take refuge in Lüth's photographs are a valued contribution. I thank all the bryophytes during the day. Snails might use them those photographers who have made their images available as a safe site to escape spiders, daddy-long-legs, and through the public domain. beetles, whereas other predators may lurk among the bryophytes. In streams, bryophytes may protect them Literature Cited from fish, ducks, shore birds, and amphibians. Anonymous. 1987. Molluscs prefer manna to mosses. New Bryophyte leafy plants and capsules can serve as Scient. 116: 25. food for snails and slugs, but some of these mollusks Bisang, I. 1996. Tracing a hornwort-consuming beast. Bryol. seem to avoid leaves with awns. In some cases the Times 86: 1-2. moss structure is such that the snails actually lose Chatfield, J. E. 1973. Aspects of feeding and growth in land weight, whereas moss paste fosters a weight gain. But snails. Malacologia 14: 391-392. in many cases, the snails may gain their nutrition from Davidson, A. J. 1988. Aspects of bryophyte herbivory. Bull. adhering algae and Cyanobacteria. In some cases Brit. Bryol. Soc. 51: 16-17. protonemata and green capsules are preferred to leafy Davidson, A. J. 1989. The Consumption of Selected Moss plants. Fissidens fontanus can be virtually eliminated Species by Slugs in the Family . Ph. D. by snails in lakes where there is no Fontinalis Dissertation, University of Reading, England,112 pp. antipyretica to protect it. Davidson, A. J. and Longton, R. E. 1985. Bryophyte But some slugs won't eat the moss even when they consumption by a generalist-feeding slug species. Abstr. have been starved for 7 days. They have even been Bot. 9, Suppl. 1: 11. Abstract only. observed retreating from a moss. Various phenolic Davidson, A. J. and Longton, R. E. 1987. Acceptability of compounds seem to be involved in their reluctance to mosses as food for a herbivore, the slug, Arion hortensis. eat some bryophyte species. Ricciocarpos natans has Symp. Biol. Hung. 35: 707-719. molluscicidal properties that are effective against snail Davidson, A. J. 1988. Aspects of bryophyte herbivory. Bull. vectors of schistosomiasis. Brit. Bryol. Soc. 51: 16-17. The moss may not offer any nutrition. Intact cells Davidson, A. J., Harborne, J. B., and Longton, R. E. 1989. of leaves, capsules, and mature spores pass through the Identification of hydroxycinnamic and phenolic acids in gut, and it seems that only young spores and Mnium hornum and Brachythecium rutabulum and their protonemata become pale during their trip through the possible role in protection against herbivory. J. Hattori Bot. digestive system. Lab. 67: 415-422. Because of their mucous trail, slugs and snails are Davidson, A. J., Harborne, J. B., and Longton, R. E. 1990. The able to disperse some bryophytes, including brood acceptability of mosses as food for generalist herbivores, branches, spores, and leaf fragments. And it appears slugs in the Arionidae. Bot. J. Linn. Soc. 104: 99-113. that the mucous helps the dispersed fragment to adhere Frahm, J.-P. and Kirchhoff , K. 2002. Antifeeding effects of to its new substrate. Spores can even pass through the bryophyte extracts from Neckera crispa and Porella obtusata digestive system and survive, thus adding another form against the slug Arion lusitanicus. Cryptogamie Bryol. 23: 271-275. of dispersal. Chapter 4-6: Invertebrates: Mollusks 75

Gerson, U. 1982. Bryophytes and invertebrates. In: Smith, A. J. (: Charopidae and Camaenidae). Memoirs of E. (ed.). Bryophyte Ecology. Chapman & Hall, New York, the Queensland Museum. 39: 343-354. pp. 291-332. Stark, R. M. 1860. A Popular History of British Mosses. George Grime, J. P. 1979. Plant Strategies and Vegetation Processes. Routledge, London, p. 8. Wiley, Chichester. Steinman, A. D. 1994. The influence of phosphorus enrichment Grime, J. P. and Blythe, G. M. 1969. An investigation of the on lotic bryophytes. Freshwat. Biol. 31: 53-63. relationships between snails and vegetation at the Winnats Stolzenburg, W. 1995. Partners in slime. Nature Conservancy Pass. J. Ecol. 57: 45-66. Sept/Oct: 7. Habdija, I., Primc Habdija, B., Matoničkin, R., Kučinić, M., Symondson, W. O. C. 2004. Coleoptera (Carabidae, Radanović, I., Miliša, M., and Mihaljević, Z. 2004. Current Staphylinidae, Lampyridae, Drilidae and Silphidae) as velocity and food supply as factors affecting the composition predators of terrestrial gastropods. In: Barker, G. M. (ed.). of macroinvertebrates in bryophyte habitats in karst running Natural Enemies of Terrestrial Molluscs. CABI Publishing, water. Biologia Bratislava 59: 577-593. pp. 37-84. Jennings, T. J. and Barkham, J. P. 1975. Food of slugs in mixed Szlavecz, K. 1986. Food selection and nocturnal behavior of the deciduous woodland. Oikos 26: 211-221. Monadenia hillebrandi mariposa A. G. Smith Kimmerer, R. W. and Young, C. C. 1995. The role of slugs in (: Melminthoglyptidae). Veliger 29: 183-190. dispersal of the asexual propagules of Dicranum flagellare. Varga, J. 2008. Analysis of the bryofauna of some moss species. Bryologist 98: 149-153. Науковий вісник Ужгородського університету Серія Leonard, W. and Ovaska, K. 2003. Jumping-Slugs!. Wings Біологія, Випуск 23: 264-265. 26(1): 9-13, 17. Wiesenborn, W. D. 2003. White desertsnail, Eremarionta Lohammar, G. 1954. The distribution and ecology of Fissidens immaculata (: Pulmonata), activity during julianus in northern Europe. Svensk Bot. Tidskr. 58: 162- daylight after winter rainfall. Southw. Nat. 48: 202-207. 173. Williamson, P. and Cameron, R. A. D. 1976. Natural diets of the Merrifield, K. 2000. Bryophytes on isolated Quercus garryana landsnail, Cepaea nemoralis. Oikos 17: 493-500. trunks in urban and agricultural settings in the Willamette Wurzel, G., Becker, H., Eicher, T., and Tiefensee, K. 1990. Valley, Oregon. Bryologist 103: 720-724. Molluscicidal properties of constituents from the liverwort Merrifield, K. and Ingham, R. E. 1998. Nematodes and other Ricciocarpos natans and of synthetic lunularic acid aquatic invertebrates in Eurhynchium oreganum (Sull.) Jaeg., derivatives. Planta Med. 56: 444-445. from Mary's Peak, Oregon Coast Range. Bryologist 101: Yom-To, Y. and Galun, M. 1971. Notes on the feeding habits of 505-511. the desert snails Sphincterochila boissieri Charpentier and Nekola, J. C. 2002. Distribution and Ecology of Terrestrial Trochoidea (Xerocrassa) seetzeni Charpentier. Veliger 14: Gastropods in Northwestern Minnesota. Final Report: 2001- 86-89. 2002 Natural Heritage and Nongame Research Program, Division of Fish and Wildlife, Minnesota Department of Natural Resources, St. Paul, Minnesota. Neumann, A. J. and Vidrine, M. F. 1978. Occurrence of Fissidens fontanus and Leptodictyum riparium on freshwater mussels. Bryologist 81: 584-585. Nyffeler, M. and Symondson, W. O. C. 2001. Spiders and harvestmen as gastropod predators. Ecol. Entomol. 26: 617- 628. Ochi, H. 1960. Conocephalum conicum, as a food for a slug. Hikobia 2: 154-155. Oyesiku, O. O. and Ogunkolade, O. R. 2006. The relationship between the Nigerian garden snail Limicolaria aurora and the moss Hyophila crenulata. J. Bryol. 28: 104-107. Pennak, R. W. 1953. Fresh-water Invertebrates of the United States. Ronald Press Co., N. Y., 769 pp. Pratt, H. S. 1935. A Manual of the Common Invertebrate Animals. McGraw-Hill Book Co., Inc., New York, p. 572. Richter, K. O. 1976. The foraging ecology of the banana slug Ariolimax columbianus Gould (Arionidae). Ph. D. Dissertation, University of Washington, Seattle. Rosso, A. L. and McCune, B. 2003. Exploring the effects of mollusk herbivory on an epiphytic lichen community. Evansia 20: 15-30. Shachak, M. and Steinberger, Y. 1980. An algae - desert snail food chain: Energy flow and soil turnover. Oecologia 46: 402-411. Smith, V. R. 1992. Terrestrial slug recorded from sub-Antarctic Marion Island. J. Molluscan Studies 58: 80-81. Stanisic, J. 1996. New land snails from boggomoss environments in the Dawson Valley, southeastern Queensland 76 Chapter 4-6: Invertebrates: Mollusks